This invention relates to a robot system for pipeline rehabilitation and more particularly to such a system that deploys an expandable patch to the location of a leak in a pipe to seal the leak.
Pipelines, regardless of the fluid they transport (water, gas, chemical fluids), often suffer from leakage. Causes of leakage may include excessive pressure within a pipe, corrosion within a pipe as a result of reactions with the moving fluid or the surrounding medium, cracks due to aging and other factors, and defects that arise as a result of poor workmanship or lack of proper maintenance.
Pipeline leakage may present serious environmental and/or economic problems. Therefore, it is important that leaks be quickly detected, located and repaired. It is often the case that pipeline networks are built as an underground infrastructure or a submerged system. Two challenges therefore exist in attempting to repair pipeline networks that form an underground infrastructure. First of all, the replacement of a defective segment of pipe may not be a reasonable choice because of the pipe's location underground. Second, an external access to a defective part of a pipe wall might not be easy to secure. In this case, a process for curing a defect in an internal wall of a defective pipe can be the appropriate approach.
There are known techniques for repairing a leaking pipe from inside the pipe. For example, spraying an epoxy coating on the inside of the pipe may be used to extend the life of an existing pipe by increasing its strength and protecting it from corrosion or abrasion. It is also known to insert a new pipe (usually plastic) into an existing defective pipe in which the old and new pipes are fused together using heat. Yet another technique for repairing a pipe from the inside is to bond a flexible fabric tube onto the defective pipe wall using a thermosetting resin followed by injection of steam or hot water for curing the resin. It is also known to insert a preformed polyethylene or polyvinyl chloride pipe formed into a U-shape before insertion into the defective pipe. Thereafter, steam or hot water may be used for expanding the U-shaped pipe to seal a leak.
It is an object of the present invention to use a robot for mechanically applying a patch to the inside of a defective wall.